The U.S. Anti-Doping Agency Friday disqualified famed cyclist Lance Armstrong's seven Tour de France titles and imposed a lifetime competition ban “as a result of his anti-doping rules violations,” the agency announced. “Mr. Armstrong chose not to contest the fact that he engaged in doping violations from at least August 1, 1998, and participated in a conspiracy to cover up his actions,” USADA wrote in a statement. USADA said Armstrong, 40, had until midnight Thursday to contest evidence against him in an arbitration hearing.

Bartolo Colon, who won the American League Cy Young Award with the Angels in 2005, was suspended 50 games on Wednesday after failing a drug test. Colon, now with the Oakland Athletics, tested positive for testosterone, according to a statement from Major League Baseball. He becomes the second key player within a week to be suspended for that substance, following outfielder Melky Cabrera of the San Francisco Giants. "I apologize to the fans, to my teammates and to the Oakland A's," Colon said in a statement issued by the Major League Baseball Players Assn.

If sport is about mythmaking, then clean sport might be the biggest myth of all. Baseball was reminded of this the hard way Wednesday when Bartolo Colon of the Oakland Athletics was suspended 50 games after testing positive for testosterone. Melky Cabrera of the San Francisco Giants was suspended 50 games last week for the same reason. Two pennant races, two key players, two suspensions - and you say your sport is clean? No sport can ever be completely clean, not with competitors eternally in search of the slightest edge.

Dodgers fans are still celebrating the 50-game suspension of San Francisco Giants star Melky Cabrera for using a banned substance, which could very well end the Giants' hopes of defeating Los Angeles for the National League West title. But there's no joy in Bay City. The San Francisco Chronicle reports that even the Giants players have turned against Cabrera, casting serious doubt on whether he will ever again appear in an orange-and-black uniform. What's less clear is whether they're mad at him for cheating, or mad at him for cheating so inexpertly.

San Francisco Giants outfielder Melky Cabrera has been suspended 50 games without pay after testing positive for testosterone, Major League Baseball said Wednesday. According to the commissioner's office, Cabrera violated the league's joint drug prevention and treatment program by testing positive for the banned substance and his suspension will begin immediately. “My positive test was the result of my use of a substance I should not have used,” Cabrera said in a statement released by the players' union.

Of all the obstacles athletes have had to overcome to compete in the Olympics, perhaps the most controversial has been the gender test. Originally designed to prevent men from competing in women's events, it is based on the premise that competitors can be sorted into two categories via established scientific rules. But the biological boundaries of gender aren't always clear. Consider the Spanish hurdler Maria Jose Martinez-Patiño. A gender test revealed that she had a Y chromosome, which normally makes a person male.

Tests attempting to distinguish men from women for Olympic competition are almost as old as the modern Olympics. But as I write in an article in today's Los Angeles Times, the science behind these tests is anything but clear-cut. Depending on the study, it is estimated that somewhere from .5% to 1.7% of people are born with some intersex condition, meaning they have at least some characteristics of both sexes. In those cases, the Olympic Committee has a decision to make: Which race will the athlete run?

The anticipated world junior-welterweight title rematch between Lamont Peterson and Amir Khan in Las Vegas on May 19 was canceled Wednesday by Golden Boy Promotions because of the fallout from Peterson's positive test for testosterone. "It's unfair to the public, HBO and the hotel [Mandalay Bay]," said Golden Boy Chief Executive Richard Schaefer , whose decision came after he was informed by the Nevada State Athletic Commission that it would conduct a special session Tuesday to weigh Peterson's licensing.

World junior welterweight champion Lamont Peterson has tested positive for synthetic testosterone, jeopardizing his May 19 title defense against England's Amir Khan at Mandalay Bay in Las Vegas. Keith Kizer, executive director of the Nevada State Athletic Commission, and Richard Schaefer, Peterson's promoter, confirmed Tuesday they've been notified of the positive test by the Voluntary Anti-Doping Assn. Kizer received a letter Tuesday explaining the result from Peterson's attorney.

World Boxing Assn. and International Boxing Federation junior welterweight champion Lamont Peterson has tested positive for synthetic testosterone, jeopardizing his May 19 title defense against England's Amir Khan at Mandalay Bay in Las Vegas, said Keith Kizer, executive director of the Nevada State Athletic Commission, and Peterson's promoter, Richard Schaefer. Kizer and Schaefer confirmed the positive result for synthetic testosterone and are now awaiting a letter Tuesday explaining the result from Peterson's attorney, both men said.